In this study, epoxy composites were reinforced with multi-walled carbon nanotubes and fused silica particles, dispersing the fillers within the epoxy resin based on a simple physical method using only shear mixing and ultrasonication. The hybrid composite specimens with 0.6 wt% of carbon nanotubes and 50 wt% of silica particles showed improved mechanical properties, with increase in tensile strength and Young’s modulus up to 12 and 37%, respectively, with respect to those of the baseline specimens. The experimental results showed that the low thermal expansion of the silica particles improved the thermal stability of the composites compared with that of the baseline specimen, whereas the thermal expansion slightly increased, due to the increased heat transfer from the exterior to the interior of specimens by the carbon nanotube filler. The coefficient of thermal expansion of the hybrid composite specimen reinforced with 0.6 wt% of carbon nanotubes and 50 wt% of silica particles was decreased by 25%, and the thermal conductivity was increased by about 84%, compared with those of the baseline specimen.

    Abstract
    1 Introduction
    2 Experimental details
        2.1 Materials
        2.2 Composite fabrications
        2.3 Measurements
    3 Results and discussion
        3.1 Evaluation of the filler dispersion
        3.2 Mechanical properties
        3.3 Thermal properties
        3.4 Electrical properties
    4 Summary and conclusion
    Acknowledgements 
    References

• Yun Oh(Division of Mechanical Design Engineering, Chonbuk National University, Carbon Composites Manufacturing and Test Center, Korea Institute of Carbon Convergence Technology)
• Jeong Seok Kang(Division of Mechanical Design Engineering, Chonbuk National University, Carbon Composites Manufacturing and Test Center, Korea Institute of Carbon Convergence Technology)
• Chang Soo Kang(Carbon Composites Manufacturing and Test Center, Korea Institute of Carbon Convergence Technology, Department of Organic Materials and Fiber Engineering, Chonbuk National University)
• Ki Chul Kwon(Carbon Composites Manufacturing and Test Center, Korea Institute of Carbon Convergence Technology)
• Gyo Woo Lee(Division of Mechanical Design Engineering, Chonbuk National University)